Plant protection mat, especially in the form of a perforated disk

ABSTRACT

A plant-protection mat, particularly in the form of a perforated disk which, in the use position above the root bale of a plant, is intended as soil covering. The perforated disk is formed from a coconut fiber nonwoven having coconut fibers bonded by latex. The coconut fibers of the perforated disk, on the one hand, are fixed by way of contour-forming stiffening edges and, on the other, the perforated disk in the region of the upper and lower covering zones, has pore structures with different opening widths.

BACKGROUND OF THE INVENTION

The invention relates to a plant-protection mat, particularly in theform of a perforated disk,

Known plant-protection mats (DE 2537056) in the form of perforateddisks, are provided as soil coverage above the root bale of plantations.The covering mats are constructed as two-layer parts with a felt layer,having jute and coconut fibers, and an additional fabric layer. Thesetwo-layer parts have to be combined by quilting or needle-punching, sothat the manufacturing expense is disadvantageously increased. Inaddition, the different materials of the covering mats cause adisadvantageously high expense during the disposal.

SUMMARY OF THE INVENTION

The invention is concerned with the problem of creating aplant-protection mat, particularly in the form of a perforated disk,which can be produced with little expenditure for material and costs inlargely any size and has a structure, stable for a sufficiently longperiod of time, so that it can be used repeatedly as a water-storing aswell as an opaque protective element and disposed of easily.

The inventive plant-protection mat is constructed as a molded object,which consists only of coconut fibers and latex and the coconut fibersof which, fixed at a contour-forming reinforcing edge, in conjunctionwith the latex particles of the nonwoven coconut fiber material, formlight-tight and at least regionally liquid-storing covering zones withpore structures improving the usefulness of the mat. Moreover, themolded object can be handled well, remains dimensionally stable evenunder rough use conditions and, while having adequate decayingresistance, enables repeated as well as long-term stable use of theperforated disks with largely any dimensions and circumferentialcontours. The disposal of such plant-protection mats is extremely easy,since their latex components and coconut fiber components can decaycompletely and, with that, the mats can be comminuted at little cost andcomposted.

The nonwoven coconut fiber material, intended for the production of theplant-protection mat, advantageously may consist of unsorted, processedcoconut fibers, which are loosened over a porcupine roller or the likefrom a crude bale, removed and supplied to a conveyor belt under theaction of gravity, so that in each case shorter coconut fiber portionsform a lower zone and longer coconut fibers an upper zone of thenonwoven sheet intended as an intermediate product. The nonwoven sheetis sprayed with a binder (latex), so that a disordered combination ofnonwoven parts is formed in the cross section of the sheet. In anappropriate embodiment, the parts by weight of coconut fiber and latexmixture supplied are equal, that is, in each case 50% by weight ofcoconut fiber and 50% by weight of latex mixture are supplied forforming the nonwoven.

Subsequently, in a continuous passage with a short residence time, thisnonwoven sheet is supplied to a severing process, carried out by meansof a punching tool, several perforated disks being severedsimultaneously from the nonwoven sheet in a single punching action.During this severing process, the contour-forming reinforcing edge isformed, in the region of which the coconut fibers and the latexcomponents, which have not cured up to this time, are consolidated underthe action of the cutting force in such a manner, that subsequently thestiffened edges impart an advantageous contour stability to theperforated disks. At the same time, the pore structures, formingdifferent opening widths, are formed in the top and bottom of thecovering zone by a consolidation of the coconut fiber-latex combination.The perforated disks, punched out of the nonwoven sheet, can becompressed to about 30% of the initial height of the nonwoven coconutfiber sheet.

In an appropriate construction, the perforated disk can also be producedfrom two layers of nonwoven coconut fibers, connected in the region ofthe stiffening edges. In this case, the layer of nonwoven coconutfibers, which is the lower one in the use position, is already preparedas a consolidated nonwoven sheet by a pressing process taking placebefore the punching process. This layer then forms the lower coveringzone with comparatively small opening width. The second sheet-shapednonwoven coconut fiber layer, consisting of loosely connected coconutfibers and latex, is placed over this nonwoven coconut layer. Afterthat, the joint severing and punching process takes place, so that aperforated disk with a stable contour and two covering zones isachieved.

For the above-described production of the perforated disks, the severingprocess also forms the radial slit starting out from the central hole.The contour of the disk, the central hole and the radial slit areproduced in one operation by the punching equipment, so that themanufacturing expense is very low.

Further details and advantages of the invention arise out of thefollowing description and the drawing, which illustrates severalembodiments of the inventive plant-protection mat in the form of aperforated disk in greater detail.

IN THE DRAWINGS

FIG. 1 shows a plan view of an inventive plant protection mat with acircular outer contour,

FIG. 2 shows a sectional representation along the line II—II of FIG. 1,

FIG. 3 A shows a plan view of the plant protection mat, similar to thatof FIG. 1, with a rectangular outer contour of the perforated disk, and

FIG. 4 shows a diagrammatic representation of the punching process forthe production of the perforated disk.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1, a plant-protection mat, shaped in the form of a perforateddisk 1, is shown in plan view. Within the circular peripheral contour ofthe mat, which has a diameter D, a central hole 2 as well as radialslots 3 and 4, emanating from the central hole 2, are clearly evident.The continuous slit 3 enables the perforated disk 1 to be positioned inthe use position above the root bale of a plant, which is encompassed inthe region of the central hole 2, so that the surrounding root bale iscovered. By way of the short slits 4, adaptation to the different plantdiameters is attained.

The perforated disk 1, constructed pursuant to the invention, is formedfrom a nonwoven coconut material, comprising only coconut fibers andlatex. The coconut fibers of the perforated disk 1, on the one hand, arefixed in the region of all contour-forming reinforcing edges 5, 6 and,on the other, form pore structures P, P′ having openings of differentwidth in the region of the top and bottom covering zones 7, 8.

In a technological appropriate embodiment, the perforated disk 1 hasessentially short coconut fibers in the region of the underside of thecovering zone 8 and essentially long coconut fibers in the region of theupper side of the covering zone P. These fibers are hooked together overthe two zones and, with the connecting latex components, form tightstructures, which have light-tight and liquid-retention properties.

The starting material for the production of the perforated disk I is anonwoven coconut fiber sheet 14 (FIG. 4) with advantageously priced,unsorted, processed coconut fibers, which are extracted from a crudebale, for example, by means of a porcupine roller or the like and reachthe transporting unit disordered, in free fall, so that, in an optimummanner for the intended end product (perforated disk), in each caseshort coconut fiber parts are concentrated at the bottom on thetransporting unit and long coconut fiber portions remain in the regionof the upper layer of the nonwoven sheet 14. During the production ofthis nonwoven sheet, a latex mixture is supplied continuously as binderin such a manner that 50% by weight of fibers and 50% by weight ofbinder are distributed in the nonwoven sheet. If necessary, anyvariation of these proportions is possible so that perforated disks 1,specifically adapted to the customer's requirements, are prepared withdifferent weights per unit area.

This coconut fiber nonwoven, in the form of the nonwoven sheet 14, issupplied to an area punch 9 (FIG. 4), which is provided in anappropriate embodiment with a repeatedly usable punching tool 10, whichspecifies a respective shape of the contour of the perforated disk 1over punching knife lines 10. These punching knife lines 10 aresupported in contour grooves in the region of the upper supporting plate12 in accordance with the circumferential contour D provided (FIG. 1) orL, L′ (FIG. 3). In the region of the contour grooves, rapid adaptationto customer-specific and application-specific contour changes ispossible with little expenditure for retooling.

In one operation (arrow K, FIG. 4), the supporting plate 12 with thepunching knife lines 11 is moved downward to a base plate 13 and thecoconut fiber nonwoven, which has an initial height E, is severed in theregion of the peripheral contour 5 or the edge of the hole 6 whilesimultaneously being pressed over the whole surface to the height E′, sothat subsequently the reinforcing edges (FIG. 1) are formed in theseregions. After this punching stroke K is carried out, the perforateddisk 1 and the rest of the material 15, left over after the punchingoperation, is transported out of the area punch 9. The rest of thematerial 15 can be worked up and used again as starting material, sothat complete processing of the crude bale is achieved.

The manufacturing process, described above, makes it clear that theperforated disk 1 is formed simultaneously during the severing processin the region of its peripheral contour 5, of the edge 6 of the hole, ofits central hole 2 and of the radial slits 3, 4 and, with that, thepressing, as well as a cutting process, bringing about the curing of thelatex—coconut fiber mixture, take place simultaneously in these regions.Subsequently, the mat components are fixed at the edge in the form of agluing, so that they can withstand stresses. When used as intended, thisperforated disk 1, which has a stiff contour, can take up water in thepore structures. At the same time, however, an unintended extensiveswelling or tearing open of the mat is avoided for a long period by thebonding strength in the stiffening edges 5, 6. Even after the bondedstructure is loosened at a later time in the region of the edges 5, 6,the protective effect of the perforated disk 1 as a whole is retained.

In a further embodiment, it is conceivable that the perforated disk 1consists of several nonwoven coconut fiber layers, which correspond intheir intended application largely to the covering zone 7, 8 and in turnare also formed from prefabricated nonwoven sheets 14. The nonwovencoconut fiber layer 8, which is the lower layer in the use position,consists of a pre-consolidated nonwoven sheet, onto which theunconsolidated nonwoven sheet is placed. After that, the perforated disk1 can be shaped by a joint severing process corresponding to thepunching described above and the two starting layers subsequently are anintegral component of the two-layer perforated disk.

When the inventive perforated disks 1 are used as soil cover, thecovering zones 7, 8 provide an adequately light-impenetrable structure,which can prevent the growth of weeds. At the same time, in the regionof the lower covering zone 8, the tighter pore structure P′ providesprotection against evaporation and also functions as a liquid and/ornutrient reservoir. The weight per unit area of the perforated disk 1advantageously is such that, especially when used on light soils,culture substrates or the like, wind erosion is avoided in the region ofthe root bale.

For improving the long-term stability of the perforated disk 1, thelatter advisably can be subjected to vulcanizing after theabove-described punching process has been carried out, so thatsubsequently, due to the connections between the latex parts and thecoconut fibers, the perforated disk 1 has advantageous elasticproperties and an improved long-term stability and the tear strength,particularly that in the region of the slits 4, is increased and thehandling of the perforated disk 1, even for repeated use with differentplant cultivations, is facilitated. The perforated disks 1 can bedisposed of without problems, since they can be comminuted at littlecost and supplied to a biological decaying process.

In the region of its contour dimensions D; L, L′, the perforated diskcan be adapted with little effort to the diameters of plant pots or thelike so that the latter are covered completely in the region of the rootbale. Likewise, for decorative purposes, it is conceivable to configurethe surface of the perforated disk 1, visible in the region of thecovering zone 8, optically attractively with, for example, coloration,advertising inscription, name embossing or the like or to provideinformation concerning use of the perforated disk 1 directly to theuser.

What is claimed is:
 1. A method of producing a plant-protection mat,comprising: obtaining coconut fibers; arranging said coconut fibers in alayer in such manner that relatively short coconut fibers areconcentrated at a bottom of said layer and relatively long coconutfibers remain in a greater proportion in an upper position of saidlayer; applying a latex mixture to said layer of coconut fibers as abinder to form a non-woven coconut fiber sheet; and forming a mat bodyof specified shape from said non-woven coconut fiber sheet prior tocuring of the latex, said step of forming including cutting a mat bodyhaving a desired peripheral contour and pressing at least an areaportion of said mat body.
 2. A method according to claim 1, wherein saidstep of cutting includes punching said mat body out of an expanse ofsaid non-woven coconut fiber sheet.
 3. A method according to claim 2,wherein said step of pressing is carried out simultaneously with saidstep of punching.
 4. A method according to claim 2, further comprising:forming at least one central hole and at least one radial slitsimultaneously during said step of punching said mat body.
 5. A methodaccording to claim 1, further comprising: preconsolidating saidnon-woven coconut sheet to form a lower non-woven coconut fiber layerwith a preconsolidated fiber structure; placing an unconsolidated uppernon-woven coconut fiber layer on said lower non-woven coconut fiberlayer prior to said step of forming; and pressing said layers togetherto form a mat body comprised of more than one layer.
 6. A methodaccording to claim 1, wherein said coconut fibers are loosened, unsortedprocessed coconut fibers.
 7. A method according to claim 1, wherein saidlatex mixture is supplied to said layer of coconut fibers in an amountapproximately equal by weight to said coconut fibers.